CROSS REFERENCE TO RELATED APPLICATIONSThis application is a continuation of copending PCT application PCT/GB00/01307, filed Apr. 7, 2000, designating the United States and claiming priority from Great Britain application 9908206.7, filed Apr. 9, 1999. The priorities of both applications are claimed herein, and the entire disclosures of both are incorporated herein by reference.
The invention relates to a waste storage device and a method of operation of such a device.
One known waste storage device is disclosed in GB Patent No. 2206094 (incorporated herein by reference) and described here with reference to FIG.1. The device is particularly useful for the storage for subsequent disposal of waste such as babies' nappies or other personal waste material. Aplastics container21 is formed with aninternal flange22 from which acylinder23 extends upwards. A pack consisting of atubular core1 inside a profusely circumferentially pleated length offlexible tubing2 is located in thecontainer21 with thecore1 resting on theflange22 and rotatable on thecylinder23. To begin using the pack to form a series of packages of objects, which in this particular example will be considered to be babies' disposable nappies, the top of theflexible tubing2 is pulled upwards and tied into aknot24. This closed end can then form the bottom of a package to be formed along the length of part of the tubing. This is effected by pushing the closed end downwards inside thecore1 andcylinder23 by the object to be packaged. As this is being done theflexible tubing2 from the pleated length slides over the top edge25 (FIG. 1) of thecore1 which is made sufficiently smooth to prevent the flexible tubing from being damaged. Thecore1 may be approximately four inches (10.16 cm) diameter but, of course, the diameter of theflexible tubing2 is substantially more Man this.
When the object has been thrust well into theconcentric core1 andcylinder23, the package is closed by twisting theflexible tubing2 above the object as at30 (FIG.1). This is done by turning thecore1 with remaining pleated tubing thereon about the core axis. A unit31 is formed for this purpose in that it has a dependingannular flange50 formed with an outer surface that is a taper fit in a frusto-conicalinner surface51 at the top of thecore1. The package is prevented from turning about the axis of the core during this manual twisting action bysprings52 fixed to thecontainer21 and projecting radially inwards to engage the package. These springs are equidistantly spaced round thecontainer21. Shallow, grooves dividing upwardly extending ridges are formed on the frusto-conicalinner surface51 to stop slippage of the flexible tubing during the twisting operating.
By the aforesaid means, a series of connected closedpackages35 are formed and this can be continued until thepleated tubing2 is exhausted. In the arrangement of FIG. 1 the packages collect in abin portion36 of the container closed at the bottom by ahinged base53 normally held closed by a manually operable catch of suitable type. When it is desired to remove the packages from thebin portion36 for transport to a waste disposal facility, the uppermost package is severed above its uppertwisted closure30 and thehinged base53 opened for the removal of the packages through the end of the bin portion. Even if the twisted seals between the packages become loosened, the lid and the newly formed topmost twisted seal with prevent the escape of odours, vapours and gases to the ambient atmosphere. However, it has been found that when thetubing2 is made of high density polyethylene the twisted joints remain remarkably tight.
A development of this arrangement is disclosed in GB 2292725 (incorporated herein by reference) and described here with reference to FIG.2. It will be seen that an outwardlyflared funnel12 having aninlet edge15 is detachably connected to the top of thecore1 by ataper joint16. The funnel improves the hygiene of the device yet further because the flexib drawn from the pack as an object is pushed down, over theinlet edge15 of thefunnel12 to present a fresh and hygienic layer of tubing in the flared part of the funnel. Thefunnel12 is twisted to obtain thetwisted closure30. Analternative spring arrangement14 is shown in FIG.2 and described fully in GB 2292725. GB 2206094 and GB2292725 both additionally disclose a cutting arrangement for severing the tubing when it is desired to remove the packages for disposal. A farther improved cutting arrangement is described in International Patent Application No. GB99/00243 which is incorporated by reference herein.
These known systems allow a simple and hygienic method of storing a large number of sanitary objects or packages such as diapers for disposal in an odour-free environment. However a certain amount of manual intervention is required for example opening lid, pushing the package through the Jaws and twisting the tubing above it. In particular in some commercial applications the user may wish to perform the operation with minimum intervention in particular to minimise contact with an apparatus containing waste from different origins.
The invention is set out in the claims. The invention provides a simple, low intervention, hygienic pedal operated system. The invention can be used without the need for twisting in one embodiment, a pair of rollers pinching a storage bag to prevent escape of odours, and the rollers may be symmetrically driven to rotate, improving the operation of the system. Alternatively a pair of paddle rollers allow the waste to be drawn down between successive pinch points. Provision of sensors allows the operation to be automated.
References herein to a storage bag or bag relate also to the flexible tubing discussed above having a knotted or otherwise closed end, or in its open configuration but acting as a bag.
Embodiments of the invention will now be described, by way of example, with reference to the drawings, of which:
FIG. 1 is a partially cut-away side view of a device of known type;
FIG. 2 is a partial sectional side view of another device of known type;
FIG. 3 is a partially sectional, schematic view showing a waste storage device according to the present invention;
FIG. 4 is a side view of the arrangement shown in FIG. 3;
FIG. 5 shows the storage of packages in the waste storage device in a first configuration;
FIG. 6 shows a detail of a means of rotating the core of flexible tubing in a waste storage device;
FIG. 7 shows an alternative inlet arrangement for the waste storage device;
FIG. 8 shows a modular component for the system;
FIG. 9 in a cut-away view of components of a second embodiment of the present invention;
FIG. 10 shows a detail of the second embodiment of FIG. 9; and
FIG. 11 shows a detail of the support arm according to the second embodiment of the invention.
The invention relates to a waste storage device of an improved type, in particular one which allows a simplified single-step operation. Referring to FIG. 3, in a preferred embodiment acontainer21 includes a pedal assembly designated generally100 which is connected via linkages described in more detail below to a pair of rollers which draw the package and flexible tubing down into the container and to means for rotating the core containing the flexible tubing to twist the tubing between the package and the lid of the container. The various linkages are spring loaded such that when the pedal is depressed the lid opens, the rollers are primed to draw the package downwards and the core containing the tubing is primed to rotate. Once the package has been inserted the pedal is released closing the lid, drawing the package downwards and finally rotating the core to close it above the packaging. As a result a fully automated system is achieved.
Referring to FIG. 3 in more detail, thepedal assembly100 includes apedal face101 projecting from a suitable aperture in thecontainer wall21, towards the base of the container allowing easy foot operation. Thepedal face101 extends from anarm115 centrally pivotally mounted on afirst pivot200. Asecond arm121 is also centrally pivotally mounted on apivot202 and symmetrically positioned about the centre line of the container with relation to thefirst arm115. In their relaxed position thearms115,121 slant downwardly towards the centre of thecontainer21 and are connected at their lower ends by a pin andslot arrangement204,206 allowing symmetrical pivotal movement of thearm121 mirroring that to thearm115 as thepedal face101 is depressed providing unproved control and operation of the system as a whole. Also connected to thearms115 and121 at the connecting point is an upwardly extendingfurther arm116 which has at its upper end a freely rotatingchain sprocket138.
Below thecore1 offlexible tubing2 are provided a pair ofrollers111, each biased into engagement with one another by arms105 (of which only one is shown for clarity) loaded bysprings208. The tubing passes between therollers111 and is pinched between them to cut off odours from the storage space below the rollers. Therollers111 are arranged for drawing flexible tubing and a package down into the body of the container. The rollers are driven by achain210 which is fixed at each end to an upper end (in the rest position) of therespective arms115,121, preferably via pivotingspring assemblies123 allowing flexibility and give in the arrangement whilst maintaining tension at all times. The chain passes over asprocket180 on eachroller111 and down around the underside of thesprocket138 on thearm116 between and below the rollers. As a result thechain210 adopts an M-configuration.
Referring to FIG. 4 it will be seen thatrollers111 interact with locking orclutch pins37,119 allowing one-way operation bychain210. The operation of the one-way drive assembly will be familiar to the skilled person, and any form of one-way drive, for example a suitable clutch is appropriate. In the version shown, as the chain passes in the first direction as the pedal is depressed, clutch pin199 which has an angled face slips over the corresponding angle-toothed face of a clutch plate, whilstclutch pin137 which has an angled face locks against the oppositely angle-toothed face of a further clutch plate. When the direction of rotation reverses, theclutch pin119 locks against the oppositely-angled toothed face of the clutch plate, whilstclutch pin137 conversely slips.Clutch pin119 is keyed to thesprocket180 via an axle through theroller111 in the embodiment shown. It will be appreciated that references to a “clutch” embrace the specific angle-toothed arrangement set out above together with any other appropriate one-way drive.
Arm115 is further biased into the rest upwardly slanted position by atension spring113 extending upwardly to an anchor point on thecontainer21.Arm121 is attached via a rigid link104 (partially shown) to apivot point212 offset from and generally above apivot hinge214 for the container lid3. Therigid link104 is also attached to the twisting arrangement designated generally150 and discussed in more detail below.
This part of the operation of the invention will now be described in more detail. As thepedal face101 is depressed thearm115 pivots in an anti-clockwise direction aboutpivot200. At the same time, by virtue of the engagement ofpin204 and slot206 thesymmetrical arm121 pivots in a clockwise direction aboutpivot202. Thepin204 and slot206 move to an over centre position such that thearms115 and121 now slant in the opposite direction from the centre of thecontainer21 downwardly. The ends of thechain210 are drawn downwardly, tension being maintained by thespring arrangements123 on the respective ends of thearms115,121. At thesame time arm116 is raised such that thechain sprocket138 is in the position shown generally as138′. However because of theclutch pin arrangement137,119, the chain slips relative to therollers111 such that they do not rotate. At the same time,tension spring113 is held under tension, urging thearm115 back to its original position.Rigid link104 is drawn downwardly byarm121, pulling the container lid3 into an open position by virtue of the offset of the pivot points212,214.
Accordingly at this stage the arrangement is primed for use, thepedal face101 in its depressed position. A package such as a diaper or other waste product is inserted into the centre of thecore1 as explained in more detail above. Thepedal face101 is then released and thearm115 is urged into its original position bytension spring113. At thesame time arm121 is also urged to its original position by virtue of the interaction ofpin204 andslot206, closing the lid3 through therigid links104. Thearm116 is drawn downwardly bringing with itchain sprocket138.Chain210 now engagesrollers111 asclutch pins137,119 now engage. As a result the rollers are driven such that their contacting faces each draw the package downwardly. The rollers are able to separate to accommodate the package by virtue of the spring loadedarms105. In order to load anew core1 withflexible tubing2 it is simply necessary to knot the end of the tubing and push it down between therollers111 so that it is securely gripped.
As a result the user merely has to depress thepedal face101 and insert the package into the open centre of thecore1. Depression of thepedal face1 preloads the system such that mere release of thepedal face101 allows the remainder of the operation to be completed without further user intervention. As can be seen the embodiment includes afunnel12 as discussed in relation to FIG.2. In addition there is provided in the preferred embodiment anouter bag220 into which the flexible tubing containing the packages is received. As a result the hygiene of the system for the user is enhanced in particular by thefunnel12, and a double-layer system is provided to reduce the risk of osmosis by virtue of theouter bag220. This arrangement is described in more detail in international application No. WO98/17536 which is incorporated herein by reference. In addition the cover has a continuously curved upper surface preventing users from resting items such as cigarette ends on it.
Referring now to FIG. 5, the packaging arrangement achieved by the invention described thus far is shown. In particular therollers111 pinch the flexible tubing above the package that has been most recently drawn through, recording risk of odour escape. In addition a tight seal and generally tight packaging as shown at34 are achieved as air is squeezed out by therollers111 allowing additional compaction of waste in a given volume. In practice this system is simple to manufacture and operate and requires minimal user effort whilst maintaining the level of hygiene and ease of use of previous waste disposal systems.
Alternatively or in addition a linkage system can be incorporated as discussed above allowing a further step of twisting the flexible tubing above successive packages. Returning to FIG. 3arm121 is further attached to an upwardly extendingrigid link110 at apivot point220 arranged above and to the right of themain pivot202 in a relaxed position. As a result whenpedal face101 is depressed andarm121 rotates in a clockwise direction aboutpivot202,rigid link110 is drawn downwardly. Attached to the upper end of thelink110 is acatch assembly109 which is generally V-shaped, withpivot point222 at the apex of the V, a point of connection to thelink110 at one end and a catch at the other end. Movement of thelink110 rotates thecatch109 into and out of engagement with astop131 on atension spring118. Thetension spring118 is attached viastop131 to acable125. Thecable125 passes around a pair of V-pulleys102,108 having axes parallel to one another and perpendicular to the axis of rotation of thecore1. The cable is attached at its other end to the upper end ofarm115 in its relaxed position.
FIG. 6 shows, between the V-pulleys102,108, thecable25 passing around an outer,rotatable support230 for thecore1 and anchored at127 thereto. Theouter support230 has an annular horizontal face on which aninner support232 for the core rests and a vertical outer face around which the cable passes. Theinner support232 is rotatable on theouter support230 but rotatably fixed in relation to thecore1 which rests upon it Rotation of the inner andouter supports230,232 can be locked by acatch107 allowing theouter support230 to rotate independently of theinner support232 in a first direction, but to lock rotation of both of them in the opposite direction. Operation of thecatch107 is again in accordance with the principles of a one-way clutch which will be well-known to the skilled person. In particular a pair of clutches having angled faces cooperating with saw-toothed clutch faces may be provided allowing simultaneous lock and slip in a first direction, and the converse in the reverse direction, as discussed in relation toclutch pins119,137 discussed above. Preferably the angle of the faces is shallow allowing reasonable freedom in the drive slipping direction.
When the foot pedal is depressed thecable12 is drawn downwardly aroundpulley102, and rotates theouter support230 in the first direction. In this direction thecatch107 is disengaged such that theinner support232 does not rotate with theouter support230. The cable passes aroundpulley108 and draws thetension spring118 into tension. Thetension spring118 is locked in that position bycatch109 which is rotated into engagement with thestop131 as therigid link110 is drawn downwardly by thearm121. In addition, as discussed in more detail above, therollers111 are preloaded, the lid3 is lifted upwardly and so forth. When thepedal face101 is released thearm115 is drawn back upwardly by virtue of thetension sprig113, rotating the rollers and drawing the packages down as discussed in more detail above. Thearm121 reverts to its original position pushingrigid link110 upwardly and rotating thecatch109 out of engagement withstop131. Thecatch109 and stop131 co-operate such that the stop is released only at the end of the stroke of therigid link110. As a result, once thearm121 has reverted to its rest position, and the package has been drawn belowrollers111,spring118 is released allowing it to contract. This draws thecable125 rapidly downwardly around thepulley108, rotating theouter support230 in the opposite direction and hence, by virtue of engagement of thecatch107, theinner support232 as well. As a result thecore1 is twisted relative to therollers111 creating a twist in theflexible tubing2 above the package. When theouter support230 stops rotating, there may be a small amount of additional rotation of theinner support232 by virtue of its momentum because of the rapidity at which thespring118 relaxes and the shallow angle on the clutch slip face in the drive direction, creating further twisting and a yet tighter seal.
FIG. 7 shows a slight variant on the arrangement of FIG. 5 in which a different shaped funnel is provided allowing certain waste items to be more easily inserted. In particular the funnel is of an elongate oval shape but any appropriate shape may be selected as long as its circumference is substantially the same as that of the circular funnel.
It will be appreciated that thepedal assembly100 including thechain210, and therotating assembly150 can be provided offset from the flexible tubing andouter bag220, as can be seen in FIG.4. As a result there is no interference between the assembly and the positioning and storage of the packages. In addition the assembly can be made in modular form as shown in FIG.8 and retrofitted to existing arrangements in any sized container.
Referring now to FIG. 9, an alternative embodiment is shown in which the foot operated system is replaced by a motor driven system. As discussed previously, the waste inlet includes afunnel303 over which a length offlexible tubing304 passes stored in acassette305, theflexible tubing304 is drawn down into a waste receptacle (not shown) below a pair ofrollers315 carrying paddles orfingers316. In the embodiment shown the paddles include rounded rubber or otherwise flexible ends320, and therollers315 are arranged to rotate in contrary directions synchronised such that, as the rollers rotate, the corresponding paddles from each roller come into engagement between the rollers. The rollers are mounted onsupport arms314 and are biased together by atension spring317 linking their axes of rotation such that the blades are pulled into engagement but the rollers can nonetheless rotate.
Amotor318 which can be, for example, a12 volt DC motor co-operates with a gear train to drive agear310 which drives afirst roller315 and asecond gear311. Thesecond gear311 drives asecond roller315 such that the two rollers rotate in contrary direction. Therollers315 preferably includegears312,313 on which the paddles are mounted.
Turning now to therollers315 once again, in the version shown five equiangular paddles are provided on each roller although it will be appreciated that any appropriate number of paddles can be adopted Each of the paddle blade tips is covered by asoft rubber extrusion320 which ensures a high coefficient of friction between the paddle blade tip and the external face of the film to prevent slipping. As a result as the paddles rotate into engagement with one another and then move generally downwards, they pull the film at the same time, a constant pinching force being introduced by the biasing of pinch springs317 (a further spring is provided at the rear, not shown).
Referring now to FIG. 10 further detail of the upper part of the waste disposal device is shown, where common reference numerals denote common parts. Mounted to the thin outer body306 are pivoting dual-type lid halves302 which pivot between a closed position (shown in solid lines) and an open position (shown in dotted lines). In the open position waste can be placed intofunnel303. The lid halves are powered in any appropriate manner to open upon detection of a waste product by infrared or otherappropriate sensor301 which is connected to appropriate control means (not shown). Onepaddle roller315 is shown in side view from which it can be seen that the paddles are planar in nature and elongate such that theirblade tips316 extend the full length of the waste aperture width such that the entirety of the flexible tubing is pinched closed between them. The transmission between the motor and gear train8 and the paddles can be seen more clearly from FIG. 10, in particular the motor shaft transmits the drive viapinion309 to gear310 (visible in FIG.9). As can also be seen from FIG. 10, in the embodiment shown, thepinch spring317 extends between the upper ends of the support arms through which theaxes322 of the rollers pass.
In operation the bin is opened by the user passing the hand in front of the infrared orother sensor301 mounted behind a lens (not shown) in the main case of the bin or receptacle306. When the beam is broken the mainouter lid302 is powered open to reveal thefunnel303 andfilm304. Control means are provided to control the operation and in the preferred embodiment the outer lid remains open for approximately 4.5 seconds giving the user sufficient time to place the waste material into the funnel. Closure of thelid302 allows themotor308 to be powered for a period, for example, of 15 seconds, the period being determined such that an appropriate length of film is drawn through the funnel. On insertion the waste material sits close to the pinch point between two engaging paddles on therollers315. As the film is drawn down and new film pulled out to replace it from thecartridge305, the waste is also drawn down into the waste receptacle (best seen in FIG.10). Once the cycle has been completed the device is ready to be activated by the next user.
Thegear train310,311,312,313 ensures that each paddle is driven by the motor as discussed above. To avoid thegears312,313 meshing their diameter is small enough that when the roller axles are closest together (the position where the paddle tips are furthest from an imaginary line joining the axles of the rollers) the gears still do not meet. Thesupport arms314 mesh with each other atpoint324 such that therollers315 are both equally displaced as waste passes between them. In the embodiment shown thesupport arms314 are meshed by providing a nose on one arm registering with a notch on the other.
To accommodate a greater range of movement, this simpler arrangement can be replaced by a gear arrangement as shown in FIG.11. FIG. 11 shows the detail of a support arm including an improved meshing feature with the corresponding support arm. As will be seen the arm includes a toothed circular portion arranged to engage with a similarly toothed or notched portion on the other arm allowing a greater degree of movement in register with one another. Preferably the arm is an H section. In particular a plurality ofteeth330 can be seen.
Theaxles326 of thelower gears310,311 rotate in bearings on the receptacle main body or fixed relative to the receptacle main body. Thesupport arms314 pivot around theaxles326 at their lower ends. Therollers315 are held in the desired position, but free to move together and apart symmetrically, by virtue of the spring connection between the upper ends of thesupport arms314 and the mesh engagement with thegears310,311.
Because paddles or vanes are provided, the waste product placed into the funnel does not have to pass through the pinch point betweenco-operating paddles320. For example in the embodiment shown, the pinch point moves downward by approximately 60 mm and the next pair of blades accordingly pinch approximately 60 mm above the previous pinch point. Packages up to 70 mm thick can be accommodated especially if the support arms are meshed as discussed above.
At the end of the operation theflexible tubing304 is once again pinched above the waste area such that users cannot see down into the waste area and odours do not escape from it.
It will be appreciated that the various possible arrangements described herein can be interchanged as appropriate both in embodiments described and the documents incorporated by reference. In addition either the simplified roller system or the simplified twisting system of FIGS. 3 to8 can be used independently of the other as appropriate. As a result the arrangements shown in FIG.3 and discussed above in which each package is separated by twists above and below it is achieved.
In addition the embodiments shown in FIGS. 8 to11 can be driven in any appropriate manner such as the batteries shown at318 or mains power. Alternative motor types can be used and indeed manual operation, for example peddle operation as in FIGS. 2 to8 can be adopted. The rollers can carry any desired number of paddles with any appropriate spacing and the various materials used will be entirely evident to the skilled person.